100-Hz Electroacupuncture but not 2-Hz Electroacupuncture is Preemptive Against Postincision Pain in Rats.

Preemptive analgesia involves introducing an analgesic before noxious stimulation. Electroacupuncture (EA) activates descending mechanisms that modulate nociceptive inputs into the spinal dorsal horn. This study evaluated whether preoperative EA is more effective than postoperative EA in reducing incision pain in rats. The nociceptive threshold to mechanical stimulation was utilized to examine the effects of an intraperitoneal injection of saline (0.1 mL/kg) or naloxone (1 mg/kg) on antinociception induced by a 20-minute period of 2-Hz or 100-Hz EA applied to the Zusanli (ST36) and Sanyinjiao (SP6) acupoints before surgical incision, or 10 minutes after or 100 minutes after surgical incision of the hind paw. The extent of mechanical hyperalgesia after the incision was significantly attenuated by the application of 100-Hz EA preoperatively, but not by its application at 10 minutes or 100 minutes postoperatively. By contrast, 2-Hz EA was effective against postoperative hyperalgesia when applied 10 minutes or 100 minutes after surgery but not when it was applied preoperatively. Only the effect of 2-Hz EA applied 10 minutes after surgery was sensitive to naloxone. The present study showed for the first time that 100-Hz EA, but not 2-Hz EA, exerts a nonopioidergic preemptive effect against postincision pain in rats.

Effect of eletroacupuncture on DU-14 (Dazhui), DU-2 (Yaoshu), and Liv-13 (Zhangmen) on the survival of Wistar rats' dorsal skin flaps.

The survival of skin flaps has great interest in many areas of Medicine. In practice, one of the most important complications in the use of skin flaps is the tissue ischemia, which frequently results in widespread necrosis and failure of the proposed treatments. The objective of this study was to evaluate the possible benefits of eletroacupuncture stimulation of the points DU-14 (Dazhui), DU-2 (Yaoshu), and Liv-13 (Zhangmen) over the skin flap survival of Wistar rats after 8 days of treatment. Forty male Wistar rats were allocated into four groups with 10 animals each. They were submitted to a surgical procedure in which a dorsal skin flap measuring 10 x 4 cm was elevated and then sutured back with a plastic barrier between the flap and the donor site. During the following 8 days, one group received electro stimulation in two "nonaccupoints" whereas the other one had the accupoints DU-14 (Dazhui), DU-2 (Yaoshu), and Liv-13 (Zhangmen) stimulated. After this period, the rats were killed and flaps were appraised qualitative and quantitatively. Data were evaluated with analysis of variance and to establish significance Fisher's PLSD test was used when analysis of variance showed P < .05. It was observed that electroacupuncture group presented a skin flap survival index remarkably larger than the others. It has also shown a better evolution during the 8 days PO, confirmed by the lowest rate of necrosis and absent area. In this experimental model, eletroacupuncture was an efficient method to preserve vitality and decrease dorsal skin flap necrosis on Wistar rats.

Electro-acupuncture efficacy on pain control after mandibular third molar surgery.

The aim of this study was to evaluate the efficacy of electro-acupuncture (EAC) on postoperative pain control after mandibular third molar surgery. Twenty four young patients (12 male and 12 female) with symmetrically impacted mandibular third molars were selected. Each patient was submitted to two separate surgical procedures under local anesthesia. At one side, extraction was carried out employing both prior (24h) and immediately postoperative application of EAC, while on the contralateral side surgery was carried out without any treatment. EAC was applied on 6 bilateral systemic and 2 auricular points with a WQ10Dl appliance using 40-60Hz frequency for 20 min and individually adjusted intensity. Postoperative pain intensity was rated on a 100 mm visual analog scale (VAS) between 2 and 72 h and recording the amount of analgesics intake after surgery. Statistical analysis was performed using theWilcoxon test. Postoperative pain VAS scores were significantly lower for the EAC group (p<0.05) and analgesic intake decreased (p<0.05) for all evaluated periods (p<0.05). Under the tested conditions EAC therapy is efficient was proved controlling postoperative pain following mandibular third molar surgical removal.

Electro-acupuncture efficacy on pain control after mandibular third molar surgery

The aim of this study was to evaluate the efficacy of electro-acupuncture (EAC) on postoperative pain control after mandibular third molar surgery. Twenty four young patients (12 male and 12 female) with symmetrically impacted mandibular third molars were selected. Each patient was submitted to two separate surgical procedures under local anesthesia. At one side, extraction was carried out employing both prior (24h) and immediately postoperative application of EAC, while on the contralateral side surgery was carried out without any treatment. EAC was applied on 6 bilateral systemic and 2 auricular points with a WQ10Dl appliance using 40-60Hz frequency for 20 min and individually adjusted intensity. Postoperative pain intensity was rated on a 100 mm visual analog scale (VAS) between 2 and 72 h and recording the amount of analgesics intake after surgery. Statistical analysis was performed using theWilcoxon test. Postoperative pain VAS scores were significantly lower for the EAC group (p<0.05) and analgesic intake decreased (p<0.05) for all evaluated periods (p<0.05). Under the tested conditions EAC therapy is efficient was proved controlling postoperative pain following mandibular third molar surgical removal.

O objetivo desta pesquisa foi verificar a eficácia da aplicação de eletro-acupuntura (EAC) na redução da dor após a exodontia de terceiros molares inferiores inclusos. Foram selecionados 24 pacientes jovens (12 homens e 12 mulheres) com inclusão bilateral de terceiros molares inferiores em posição similar. Cada paciente foi submetido aleatoriamente a dois procedimentos cirúrgicos em dias diferentes: em um deles o dente foi extraído com uma sessão pré-operatória (24 h) e uma pós-operatória imediata de EAC enquanto no outro a extração foi feita sem EAC. A EAC foi aplicada em 6 pontos sistêmicos bilaterais e 2 auriculares com um aparelho WQ10D1 utilizando freqüência de 40-60 Hz por 20 min com intensidade ajustada individualmente. A dor foi avaliada desde 2h até 72h pós-operatórias utilizando a escala visual análoga (EVA) de 100 mm e pelo consumo de analgésicos. Os dados foram comparados pelo teste deWilcoxon. Os escores de dor da EVA foram significantemente menores para o tratamento com EAC (p<0,05) enquanto o consumo de analgésico diminuiu (p<0,05) em todos os períodos (p<0,05). O tratamento com EAC mostrou-se eficiente no controle da dor pós-operatória após cirurgia de extração de terceiros molares inferiores inclusos.